Ford claims 412 HP. American Racing Headers say it's considerably more! The new 5.0L Coyote Mustang is here and quicker than you can blink, ARH has a header system.

Manufactured from 304 stainless steel, ARH's longtube systems are engineered for a great fit and outstanding horsepower and torque gains throughout the RPM range. Through stock mufflers and mid pipes (and no tuning) power was up 32 RWHP. Made in the U.S.A.

*Please Note: Ford changed the thread pitch on the header bolts midway through productions. 5.0L Mustangs made from March 2010-August 2010 should order the kit that includes fine thread bolts, 5.0L Mustangs made after August 2010 should order the kit that includes coarse thread bolts. *Please select the correct headers for your application.

By Bill Tumas:
A couple of months ago we showed you the benefits of the American racing headers that we installed on our 2013 Gotta Have It race car. The fit and finish was excellent and they make great power as well. Today we're going to install a set on this 2011 Mustang GT. Since this is primarily a street car we're going to go with a three inch X-Pipe with the high flow cats and their 1-7/8" headers.

Once you've disconnected your battery the first step is to lock your steering column. Since we're going to disconnect the steering shaft for the installation, if you don't lock the column the wheel could spin freely and damage your airbag clock spring. With the key out, just turn the wheel until it locks.

Since we're going to be disconnecting the steering shaft we're going to remove these two bolts for the steering plate going through the firewall. Once you remove the nuts you want to pry the plate away from the firewall. A 2011 already has a supercharger on it and so the stock headers are probably costing us some horsepower. We're expecting some pretty good gain with the American racing headers.

We're going to loosen up the motor mounts on our driver's side. We're going to remove the bolts on our passenger side to give us more room. Now under the car we're going to remove our H-Pipe. Start by removing the O2 sensors. Now we're going to remove our cross member.

Now we're going to remove the clamps from our exhaust. Now we'll disconnect the H-Pipe from our factory headers. We're going to remove the H-Pipe from our tailpipe. It's a good idea to have a hand here to have someone hold it for you while you hammer them free. Now we're going to remove the oil service pin. Now we're going to remove the starter.

We're going to use our pole jack to support the engine so we can remove the motor mount from the passenger side. You want to jack it up on the corner of the pan to make sure you don't damage the oil pan. Next you want to remove this harness from the stud and now you can remove the bolts.

Now we can remove the motor mount bracket and remove the motor mount itself. Now that everything is out of the way you can access the header bolts. The best way to get these is with a longer extension out beside the control arms. You want to leave on of the easier ones to last. Get the harder ones first. That way the easy one will hold the header in place and you can remove that and pull the header out in one assembly.

Now is a good time to disconnect your front O2 sensor. For some of the upper bolts it's easier to get them with a ratcheting wrench. Now remove the last bolt to free the header and it'll fall down just a little bit. We're going to choose to reuse the factory studs so we're going to leave them in the heads. We want to make sure the AC lines are clear before you try to pull the header out.

Once you remove the header you want to remove the factor gasket since it's not used with the American racing headers. The kit includes four oxygen sensor extensions. The short ones are going to go to your front sensors and the longer ones will go to the rear.

Since the American racing headers don't require gaskets, we're going to put a little bit of copper gasket sealant on the head before we install the header. Now we're ready to put our header up into place. Once you have the header in place you want to put one of the nuts on the studs to hold it in place. You may have to remove one or two of the studs if it's tight. Usually you can get it on without taking any of them off.

Once the header is tightened up you can reinstall your oxygen sensor followed by your motor mount and bracket. Make sure you zip tie the harness safely away from the header. Once you're finished with the passenger side the first step in doing the driver side header is to disconnect the steering shaft.

I'm going to push the shaft up and out of the way. Now we're going to remove the motor mount bolts that we loosened earlier. We can start removing the header bolts. Now we're ready to remove our header. Now we're going to install the copper gasket sealant on our driver's side head before we put our new header on. Now we're going to slide our header up into place.

Once we get it up into place we're going to put one nut in to keep it in place so we can get started on the rest. Once your header bolts are tight you're ready to reinstall your oxygen sensor, as well as your motor mount, and then your motor mount bracket. Now we're going to reinstall the steering shaft and the coupler. Reinstall the oil service shield. Now we can reinstall the cross brace. You want to assemble the catalytics into the X-Pipe off the car. Keep everything loose so you can fit it easy once you have it in place. You also want to put the O2 sensors on in advance as well.

Start by connecting to the header side first. The last step is to connect the rear O2 sensors with the supplied extensions. You'll want to zip tie those safely out of the way.

We're excited to hear how our new headers sound, but you want to make sure you don't forget to screw in the plate underneath the dash for the steering column before you take it for a test drive. Now we're ready to fire her up and see how she sounds.

Our new headers sound great. Can't wait to get her on the dyno and see what kind of horsepower we've got. Just as we've come to expect from American racing headers, fit and finish was excellent, the sound is amazing. Installation figure on about six to eight hours, you'll be back on the road in no time.